A conventional air conditioning system employs evaporation heat which is absorbed by refrigerant from the surroundings when the refrigerant evaporates. As the refrigerant, liquids such as ammonia, Freon, an azeotropic refrigerant mixture, chloromethyl, and so on, which can easily evaporate even at low temperatures, are generally used.
In the conventional air conditioning system, as a vaporized refrigerant, which is compressed by a compressor to a high pressure, flows through a condenser, the refrigerant exchanges heat with the outside air, and condenses to a liquid refrigerant having a high pressure. The liquid refrigerant having a high pressure is then converted into a low pressure liquid refrigerant after passing through an expansion valve or a capillary tube.
The low pressure liquid refrigerant enters an evaporator, exchanges heat with indoor air, and evaporates. Thereafter, the evaporated low pressure refrigerant enters the compressor to complete an air conditioning cycle which is continuously repeated. The air cooled by the uptake of evaporation heat by the refrigerant in the evaporator is directed to a target space or object by a blower fan to conduct a cooling function.
The conventional air conditioner uses refrigerant which can easily undergo a phase change, such as through condensation and evaporation, to cool a target space or object.
Meanwhile, in a base station or a communication car, various wired or wireless communication equipment is installed. The communication equipment is likely to have loose connections or to break down due to frequent heat generation, whereby the possibility of malfunction increases. For this reason, it is necessary to cool the communication equipment all year round to ensure reliable operation thereof.
However, in the conventional air conditioning system for communication equipment, since naturally cold outside temperatures are not appropriately used and the air conditioning system is driven only by electric power, electric power is wasted.